Simple way to set up Split DNS

TomEastep

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What is Split DNS

Split DNS is simply a configuration in which
the IP address to which a DNS name resolves is dependent on the location
of the client. It is most often used in a NAT environment to insure that
local clients resolve the DNS names of local servers to their RFC 1918
addresses while external clients resolve the same server names to their
public counterparts.

If your local hosts are configured using DHCP, that is a simple
one-line change to the DHCP configuration.

And that's it! Your local clients
will resolve those names in the firewall/router's
/etc/hosts file as defined in that file. All other
names will be resolved using the firewall/router's Name Server as defined
in /etc/resolv.conf.